Switching device



March 10. 1925. 1,528,767

c. J. HENDRICKSON SWITCHING DEVICE Fild April 27, 1922 3 Sheet$ Sheet 1 Patented Mar. 10, 1925 UNITED STATES I 1,528,767 PATENT OFFICE.

CHARLES J. HENDRIOKSON, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SWITCHING DEVICE.

Application filed April 27, 1922.

To all whom it may concern:

Be it known that 1, CHARLES J. HENDRICK- SoN', a citizen of the United States, residing at New York, in the county of New York, State of New York, have invented certain new and useful Improvements in Switching Devices, of which the following is a full, clear, concise, and exact description.

This invention relates to automatic switching devices used in the establislnnent of electrical circuit connections. It has to do more especially with switching devices of the character employed in telephone systems for the purpose of connecting and disconnecting telephone circuits.

In certain classes of electrical switching apparatus the circuit-making contacts consist of comparatively simple elements which are brought into engagement with each other by means of a single movement of slight magnitude. These circuit-making contacts may comprise plain bare wires or other forms of electrical conductors. A plurality of these conductors have points of cooperation with each other and some actuating means is provided for selecting a desired conductor and moving it through a slight distance into physical contact with another conductor, thus establishing the desired connection. The contact actuating means, which in addition to imparting the necessary movement to the contacts also de termines their selection, comprises a plurality of mechanical switching members such as rods or bars. By selecting and operating a number of these bars snnultaueously, sequentially, or in any other suitable fashion, they may be madeto cooperate for the purpose of selecting and operating the contacts necessary to establish the connection required.

Accordingly the object of the present invention is an improved switching mechanism of the foregoing general character.

A feature of the invention relates to a switching device for interconnecting lines in which a plurality of switching members when actuated together cooperate with each other to select and move another switching member identifying the line to be connected.

Another feature relates to an arrangement in which a switch operating member, identifying a group of lines, and a switch .terinine the selection and Serial No. 556,935.

operating member identifying the location of a particular line in the group, when operated jointly, select and operate another switch ope-rating member which prepares said particular line for connection with any of a plurality of other lines.

Still another feature relates to a switching device in which the joint operation of one of a plurality of operating members arranged in one plane and one of a plurality of members arranged in a parallel plane selects and operates one of a plurality of members arranged in a plane perpendicular to said planes for determining a circuit connection.

Such other and further features as are contemplated by the present invention will become apparent from the following detailed description and also from the appended claims. 7

Referring to the drawing, Fig. 1 is a side view of a portion of the switching structure.

Fig. 2 is an end view of the switch and likewise illustrating only a portion thereof.

Fig. 3 is a top elevation showing in schemat-ic manner a complete assembly of the operating and switching members which comprise the switching device.

Fig. .l is a perspective view showing in detail the arrangement of the operating and Switching elements.

Fig. 5 shows a circuit arrangement for operating the switch.

The switching device embodying the features of this invention is one which preferably involves the coordinate principle of selection and operation. A plurality of sets of operating members or bars are provided which, when actuated in coordination deoperation of the proper circuit-making contacts.

For convenience in description, the switch is illustrated as having a capacity for effecting connections between lines of a group, of which there are one hundred lines, and the lines or trunks of a second group, of which there may be any desired number, Such, for example, as ten lines or trunks. It is to be understood, however, that the switch may be constructed to accommodate groups of lines of varying capacities with out departing from the scope of the invention. The connection between the different lines is accomplished by means of circuitmaking contacts which comprise bare Wires, some being passive and some active, the ac tive Wires being advanced into engagement with the passive wires by operating-1nembers. Other types Of-C11'CH1t-m2tk111g contacts may be employed, if desired, instead of the wire contacts, without affecting the operation of the switching mechanism.-

A detailed description will now be given of the construction and method of operation of the switch. The structure, comprises three sets of operating switching -members which, in the present embodiment, take the form'iof rotatable bars. Referring first to Fig. 3, the firstset is seen to consistot ten operating bars'=1',- 2, 74', 75, 7'6, etc.-,all of which are arrangedin a single plane. Eaclr of the=bai's 1, 2,74, etc., pertains to a group of tenlines and when operated; serves-to determine the selection of 'the"entir,e corresponding group of ten'lines. For operat-' ing these barsa set-of tenindividual magnets 7, 77, 78, 79, 80, etc.,-is provided. The

energiZation-ot any oneof these"mag-nets causes the==rotation -ot the individual bar identifying the corresponding group oi ten lines:

Located'inan adj acent and parallel plane is a second set of operating 'ineinbers*coir-- sisting of ten bars 3, 4, 81, 82, 83, 84,.etc. Each of the bars 3, 4, 81, etc., pertains to ten different linescoinpri'sing the t'eiifcor-. responding lines, 1 one in each of .the' ten The third set. of. operating members 'like- 1 wise comprises a pluralityof rotatable bars and one of these is provided'for each line; The bars of. the third set are arranged in groups corresponding to the groups of lines and are disposed inplanes perpendicular to the planes of thefirst two mentioned sets of bars. This arrangementisbest' seen in Figs- 1, 2 and 4. In Fig. 3', the operating bars ot' the third set, which are individual to the lines in the third group of linesfiarelustre-ted y the characters 89, 90,01, 02. 93, etc.,

The operating bars 1, 2, 74, 75, etc., relat-' ing to: the groups of lines, are arranged to cooperate with any of the bars 3,4, 81', 82, 83, etc., relating tolinesin the groups, to

selectand mechanically operate a bar in the third set to identify a particular linef Each oi' the bars of the third set such as the switching bar 8 in Fig. 4, whenoperated, preparesthe contactsot the line to which it is individual for connection with any one of a plurality of trunks. The connection of a particular trunk to 'the selected line is efl'ected by the cooperation between the switching bar 8 and a bar such as 56 relating to an idle trunk. 1

Considering the details of the structure as depicted in Figs. 1,2 and 4, the operating bars 1, 2, 74, 75, are arranged in intersecting relation with the operating bars 3, 4, 81, 82. The rotatable bar 1 is provided with a plurality of projecting fingers 13, 71,

-72, etc., one at each point of intersection with oneot' the bars 3, 4, 81, etc.

Correspondingly' at these points of intersection, the bar 3, for example, is equipped with extending arms-5, 6, etc." The same ar' i'angement exists for allot the remaining bars of thesets. suitably journaled in the frame'oif the structure (not shown) and is rotated by means of an electromagnet 7, the armature 20, of -which isattached to the end of the bar] A spring 19 normally holds the bar 1 in its retracted position.

Likewise the bar 3 and all remaining bars oi the set are pivoted at their ends in the 'switchiraineand provided with an electro- "The operating bar 1 is magnet 12 serving to rotate the" same through a slight angle. Retractile springs are also provided for the several bars of this set to hold them normally in their iiioperativeposition. The switching bars 8,

9, 1Q, 11, etc.,one of which is located in. "PlOXllllltY to 'ea'chpoint of intersection between the operating bars of the first two sets,"ext end perpendicularly as 'shown in 7 Figs. 1, 2 and 4 to the planes containing the said'opei'ating bars. The bar 8, which is located at the point of intersection between bars land 3, is provided with alever 15 adapted, as explained hereinafter, to cooperate with 'the finger 13 and the arm 5. The bar 8 is normally held in its unoperated position by means of a retractile spring 17. Similarly, the switching bar 9 ISPTOVlClGCl with a .lever 16 cooperating with finger 14 and the arm 6 and also a retiactile spring 18. x The same provision is made'with re spect to all remaining switching bars int-he structure.

Attention will now be given to the contact making portion of the switch whereby any one of the one hundred lines may be connected to anyone of a group of ten trunks, for example.- Two of the lines 21 and 22 only are illustrated in Fig. 1. The line 21 is served by the switching bar 8 and may be connected to anyone of the ten trunks through the cooperation of the bar '8 and elements 54, 55, etc., relating to said trunks. the switching bar 9 which cooperateswith the elements 54, '55, as will be explained hereinafter to connect said line to any one Similarly, the line 22 is served by lii) 'necting said line to the trunk 23.

of the ten different trunks. The same relation exists between all other lines and said trunks.

In Figs. 1 and 2, three of the ten trunks are illustrated. The trunk 23 is provided with a set of multiple wire conductors 24, 25 and 26 which extend before ten switching bars 8, 10, 11, etc. Furthermore, this trunk is provided with a second set of multiple conductors 27, 28, 29 which extend be fore the ten switching bars of which the bar 9 is one. In this identical manner, the trunk 23 is provided wit-h eight other sets of multiple wire conductors extending before the eight remaining sets of switchin bars, as best illustrated in Fig. 2.

The line 21 is equipped with a set of movable contact wires 39, 40, 41 for con- These movable contact wires are supported by an insulating block 52 suitably supported on the switch-frame and extend as shown in Figs. 1, 2 and 4 through diagonal slots in an insulating card to a point where they cooperate with the multiple wires 24. 25 and 26, respectively, of the trunk 23. The insulating card 50 is supported by means of two flat flexible springs 38 and 42 which are secured to the block 52. In an obvious manner the line 21 appears in corresponding sets of movable wire contacts extending through insulating cards 69, 70, etc., for co operation with the multiple wire conductors of each of the remaining trunks in the group. Two other such trunks are represented by the conductors 90, 91 and 92 and 93, 94 and 95.

The line 22 is provided with movable. contact wires 45, 46, 47 extending through diagonal slots in the insulating card 51 for cooperation with the multiple wires 27, 28 and 29, respectively, of the trunk 23. Similarly, this line is provided with corresponding movable wire contacts for cooperation with multiple conductors 32, 33 and 34 of the second trunk and multiple conductors 35, 36 and 37 of the third trunk, etc. The movable wire contacts of the line 22 are secured to the insulating block 53 which also carries the supporting strips 44 and 48 of the insulating card 51 and similar supporting strips for other cards.

Any one of the several trunks is arranged to be connected to any one of the one hundred lines through the cooperation of the switching bar individual to a particular line and trunk operating bars relating to the trunk to be connected. For the first trunk 23 there are provided ten rotatable trunk operating bars, two of which 56 and 58 are shown. The bar 56 extends in intersecting relation before the ten switching bars 8, 10, 11, etc., allotted to the first group of ten lines containing the line 21. Bar 58 similarly extends in intersecting relation before the ten switching bars corresponding to the second group of ten lines, including the line 22. The eight remaining trunk operating bars are disposed in like manner before the eight remaining rows of switching bars.

Arranged in common to the ten operating bars 56, 58, etc., assigned to the trunk 23, is a connecting rod 54. The operating bar 56 is attached to the connecting rod 54 by means of the crank arm 57. The operating bar 58 is attached to the connecting rod 54 by means of crank arm 59. In an identical manner the remaining eight operating bars are connected to the rod 54. The extreme end of the connecting rod 54 is pivotally attached to the armature of an electromagnet 64.

The trunk operating bar 56 is provided with a series of ten levers 60, 96, 97, etc., one for each of the switching bars 8, 10, 11, etc. As best seen in Fig. 2, the levers 69, 96, 97, are disposed immediately beneath the insulating cards 50, 98, 99, supporting the wire contacts of the respective lines. The other trunk operating bars attached to the connecting rod 54, are also equipped with levers similar to those described which cooperate with the insulating cards carrying the contacts of the remaining lines.

lVith the connecting rod 54 in its normal position as shown, the levers 60, 96, 97, 61, etc., are all tilted downwardly so as not to interfere with the movement of the flexible wires 43, 101, 102, 49, etc., carried by the switching bars. The bar 8 may be rotated to carry the flexible wire 43 against the notch provided in the lower end of the insulating card 50 immediately above the curved surface of the lever 60 and so long as the connecting rod 54 remains in its normal position, the flexible wires may be withdrawn without interference by the lever 60. Similarly, any of the switching bars may be operated without interference from the levers carried by the rod 54.

Considering the second trunk, there is provided a corresponding set of trunk operating bars 62, 63, etc., carrying the levers 67, 68, and attached to a connecting rod which is controlled by the armature of the electromagnet 66. All of these elements are disposed and perform similar functions to those described in connection with the trunk 23. The same is true of the remaining trunks in the group.

The operation of the switching device is best understood from the perspective view in Fig. 4. Assume that it is desired to establish a connection between the line individual to the switching bar 8 and an idle trunk or other line. Referring to Fig. 3, this particular line is seen to be in the group of ten controlled by the electromagnet 7 and is the particular line of that group controlled by the electromagnet 12. Hence by any suitable circuit arrangement, such as shown inFig. 5, the circuit of magnet 7 is closed and this magnet becomes energized to attract its armature 20. Armature 20 rotates the operating bar 1 against the ten.- sion of spring 19 carrying the ten fingers 13, 71, 72, etc., into alignment with the corresponding arms 5, 73, etc., on each of the respective operating bars 3, 4, 81, 82, etc.

During the time that magnet 7 is maintaining the bar 1 in its set position, a circuit is also prepared for the magnet 12. Magnet 12 attracts its armature and rotates the individual operating bar 3. Since the finger 13 on the bar 1 has been placed directly in line with the path of movement of the arm 5, as best seen in 4, said arm in its rotation first engages the finger 13 and flexes the same, carrying it into contact with the lever 15 attached to the switching bar 8. The continued rotation of the operating bar 3 presses the finger 13 against the lever 15 and the bar 8 is rotated against the tension 0t spring 17. All of the remaining arms, such as the arm 6 on the bar 3, are likewise rotated, but since none of the other bars 2, 74, 75, etc., are positioned, these arms tail to encounter the cooperating flexible fingers. Hence only the one switching bar 8 is selected and actuated due to the cooperative movement of the two operating bars 1 and 3. y

The rotation of bar 8 carries the flexible wires 43, 103. 104 against the notched edges of the insulating cards 50, 69, 70, etc. Thus ten different sets of contacts for the desired line, engaged by the cards 50, 69, 70, are prepared for connection with the multiple wires of any one of the ten different trunks. All that is necessarv to effect this connection is to operate one of the magnets 64, 66 individual to the proper trunk to cause the movement of the corresponding insulating card 50, 69, 70 to carry the movable contact wires into engagement with the multiple wires of the trunk.

Assume that the first trunk 23 is idle. By a suitable circuit arrangement the electromagnet 64individual to the trunk 23 is energized. Magnet 64 attracts armature 65 which moves the connecting rod 54 to the left as viewed in Fig. 1. The connecting rod 54 through the crank arms causes all ten of the trunk operating bars 56, 58, etc., to rotate. The rotation of these bars causes the levers 60, 96, 97, 61 to tilt upwardly. Since the flexible wire 43 has-been moved directly into alignment with the lever 60 on the bar 56 said lever first encounters the flexible wire 43. of the bar 56, the wire 43is carried against the lower edge of the insulatingcard and said card is moved upward bodily to carry the wire contacts-39, 40, 41 ot the desired line into engagement with the corre- In the continued rotation spending multiple wire terminals 24, 25 and 26 or" the trunk 23. The diagonal arrangement of the slots in the card 50, through whichthe contact wires pass, causes a rubbing action of the said contact wires on the multiple wires 24, 25 and 26 of the trunk. All of the remaining levers 96, 97, etc, controlled by the magnet 64 are also tilted upwardly but since only the bar 8 was operated none of the corresponding flexible wires 101, 102, is in position and hence no other contact set is moved into engagement with the trunk wires. 7

As soon as the magnet 64 has operated,

the magnets 7 and 12 may be deenergized to release the bars 1 and 3, respectively. Lever 5 and the flexible finger 13 restore to their normal positions disengaging the lever.

The spring 17 immediately restores the wire firmly against the lower edge of the card 50 whereby it flexes when the bar 8 restores to, normal but cannot become dis engaged until the lever is released.

lVhe'n the connection is no longer desired, the switch is restored to its normal condition by the simple act of deenergizing the magnet 64. The magnet 64 releases the connecting rod 54' and all of the associated trunk operating bars are restored to their normal condition, whereby the flexible wire 43 is released and the insulating card 5t restores under the influence of supporting springs 38 and 42.

During the continuation of a connection, the operating bars and switching bars may be reoperated to connect any other line terminating in the switch with any idle outgoing line or trimk. It is obvious that the switch may be employed as above described to'connect one of a large number of incoming lines to one of a less number of outgoing trunks or, reversely, may be employed to connect one. of a small number of incoming trunks. to any one of a larger number of outgoing lines, serving in the first instance as a line finder and in the latter instance as a connectorswitch.

The notched surface of the lever.

. A description will now be given of Fig.

5 in which is i lustrated onetorm of circuit arrangement for operating the switch disclosed in this application. Three lines 21, 22 and 116 are shown and also three trunks 23, 114 and 115. Lines 21 and 22 maybe considered as the first and second lines in the first group of ten, served by the operating bar 1 and magnet 7, referring to Fig. 3. Line 1.16 is the first line of the second group, such as the group served by result of this the particuar units magnet.

indentifying the calling line is likewise energized. When a line in the second group originates a call the group magnet 77 individual to such second group becomes operated and thereupon the particular units magnet indentifying the calling line in the second group is also operated.

As a result of the joint operation of a group magnet and any one of the units magnets, the trunk magnet individual to the first idle trunk is operated to complete the connection from the calling line to the idle trunk. The trunk magnets 64, 66 and 117 individual, respectively, to the three trunks 23, 114 and 115, are shown.

It the subscriber of line 21 initiates a call, a circuit is closed over the loop of his line for the operation of relay 105. Relay 105 closes a circuit from ground, through its inner contact, winding of group relay 7, to

battery. Relay 7 operates and a circuit is closed from ground, through the left con tact of said relay, outer contact of relay 105, winding of the units magnet 12 to battery. The magnet 12 operates to rotate the bar 3 which coacts with the finger 13 to rotate the switching bar 8.

Vith the magnet 12 operated and magnet 7 energized, a circuit is closed from ground, through the contact of magnet 12, right contact of magnet 7 to the starter wire 118.

Assume that the first two trunks shown, namely, trunks 115 and 114 are busy. In this case the relays 111 and 112 are operated to extend the starter wire 118 through to the next trunk 23 which is the first idle one to be encountered. The starter wire 118 may, therefore, betraced through the front contacts of relays 111 and 112, through the back contact of relay 113, winding of the magnet 64 to battery. Magnet 64: operates and in the manner heretofore explained completes the connection between the line 21 of the trunk 23.

By any suitable arrangement, well known in the art, a ground potential is applied to the sleeve conductor of the trunk 23 and a circuit is thereupon closed for the operation of relay 113 and also a holding circuit for magnet 64. Relay 113 extends the starter wire through to the next trunk magnet. The ground on the sleeve also causes the operation of the cut-off relay 106. Relay 106 opens the circuit of the line relay 105 and the circuits of magnets 7 and 12 are thereby opened. These magnets become released to restore the mechanical parts which they control. The connection is held by the continued energization of the trunk magnet 64 which has a circuit cosed to the grounded sleeve conductor of the trunk 23. At the end of, the conversation when the subscriber replaces his receiver on the switchhook, ground is removed from the sleeve conductor in the usual manner and the magnet 61 releases to completely restore the switch to its normal condition.

Had the second subscribers line 22 been the calling line then the group magnet 7 and the individual magnet 85 would have been operated together with the trunk magnet representing the first idle trunk in the series.

Had the subscribers line 116 called, this being the first line in the second group, then the group magnet 77 and the individual magnet 12 would have operated to establish the connection in the same manner.

What is claimed is:

1. The combination in a switching device of a plurality of operating members, switching members, a plurality of lines one for each switching member, means for actuating a plurality of said operating members, said actuated members cooperating to select and actuate one of said switching members, other lines, and means controlled by a switching member for connecting the corresponding line to any of said other lines.

2. The combination in a switching device of a plurality of operating members, switching members, a plurality of lines, one for each switching member, individual magnets for actuating a plurality of said operating members. said actuated members cooperating to select and actuate one of said switching members, other lines, and means controlled by a switching member for connecting the corresponding line to any one of said other lines.

3. The combination in a switching device of a plurality of operating members, switching members, a plurality of lines, one for each switching member, means for actuating a pair of said operating members to jointly and cooperatively select and actuate one of said switching members, other lines, and means controlled by a switching member for connecting the corresponding line to any of said other lines.

4. The combination in aswitching device of a plurality of rotatable operating members, rotatable switching members, a plurality of lines one for each switching member, means-for rotating a plurality of said operating members, said last mentioned 1 members cooperating in their rotation to rotate one of said switching members, other lines, and means controlled by a switching member for connecting the corresponding linet-o any of said other lines.

,necting the corresponding line to one of said otherlines.

6. -The combinat on 1n a swltchmg device not sets of operating members, switching -members, a plurality of lines, one for each ,switching member, means for actuating an operatingmember in each of said sets, said actuated members cooperating to select and actuate one of said switching members, other l1nes,-and means controlled by a switching member to connect the corresponding line to saldother hnes.

7. The combination in a switching device of sets of operat ng members, swltchmg members, l nes, one for each switching mem- ,ber, means for actuating any operating member in eaclrof said sets, said operating members, when in actuated condition simultaneously cooperating with each other to select and actuate any one of said switching members, other lines, and means controlled by a switching member for connecting the,

corresponding line to any or" said other lines.

8. The combination in a switching device .of a plurality of operating bars, switching bars, a plurality of lines, one for each other lines.

switchingabar, means for actuating a plurality or said operating bars, said actuated bars cooperating to select and actuate one ,of said switching bars, other lines, and

means controlled by a switching bar for connecting the corresponding hne to any of said 9., The combination in a switching device having a first set and a second set of operat- 1ngmembers and a set of swltchlng members, of a plurality of lines, one for each of sziidswitching members, a third set of operating members, another line, means for ;-t(3tll2tt111g anoperating member in each of .,the firstand second sets to select and actuate oneofsaid switching members, and means,

-for, act.uating said operating members of the third set, one of said actuated members and a member of said third set cooperating,

,to connect the corresponding one'of said first linesto saidother line.

10. The vcombination in] a switching de- ,vice, hav;ing afirst set and a second set of tuating an operating member in each ofthe.

operating'members and a set of switching members, of lines,'one for each of said switching members, a third'set of operating members, another line, means for actuating an operating member in each of the first and second sets to select and actuate one of said switching members, and a single means for actuating all the operating members of the third set, one of said actuated switching members and a member in said third set cooperating to connect the corresponding one of said'first lines to said other line.

11. The combination in a switching do vice having a first set and a second set ot operating members, and a set of switching members, of lines, one for each or said switching members, a third plu *ality of sets of operating members, a trunk for each of said last mentioned sets, means for actuating an operating member in each of the first and second sets to select and actuate one of said switching members, and means for ac tuating the operating members of any of said third sets, one ofsaid actuated switching members and a member of said thirdset cooperating to connect the corresponding one of said first lines to the corresponding one of said trunks.

12. The combination in a switching device of lines arranged in groups, a. set ofopcrating members, one for each group of lines, a second set of operating members, each representing the corresponding line in all, groups, a switching member serving each of said lines, means for actuating any operat-ing member of the first set to select a group of lines, vmeans for actuating any member. of the second set to select a. particular line in the group, said actuated members cooperating to actuate the switching member representing the selectedline, other lines, and means controlled by the switching member for connecting the selected line to one of said other lines;

13. In combination in a switching device of lines arranged in groups, a. set of operat ing bars, one for each group of lines, a second set of operating bars, each representing fthe corresponding line in all groups, a

switching bar serving each of said lines, means for actuating any operating bar of the first set to select a group of lines,means for actuating any bar of-the second :set to select aparticular switching bar, said actuated bars cooperating to actuate the switching bar representing the selected line, other lines, and means controlled by the switching bar ,for connecting the selected line 'to said other lines. a

14. The. combination in a switching device of two sets of operatingmembers, each set arranged'in a separate plane, a set of switching members arranged in a plane intersecting said first planes, means-for acfirst two sets to select and actuate any of said switching members, and a plurality of independently operable circuit-making contacts controlled by each switching member.

15. The. combination in a switching device of two sets of operating bars, each set arranged in a. separate plane, a set of switching bars arranged in a plane perpendicular to said first mentioned planes, means for actuating an operating bar in each of the first two sets. said actuated bars coop crating with each other to select and actuate any one of said switching bars, and a plurality of independently operable circuitmaking contacts controlled by each switching bar.

16. The combination in a switching de vice of two sets of operating bars, each set arranged in a separate plane, a plurality of sets of switching bars, each set arranged in a plane perpendicular to the first mentioned planes, means for actuating an operating bar in each of the first two sets, said actuated bars cooperating to select and actuate a switching bar in one of said sets, and a plurality of independently operable circuitmaking contacts controlled by each of said switching bars.

17. The combination with a line of a switching device comprising more than two operating members, a second line, and means for moving said members sequentially and jointly, said members coacting mechanically to connect said first line to said second line.

18. The combination in a switching device of a plurality of operating members, switching members, a plurality of lines one for each switching member, means for causing a plurality of operating members to act cojointly in the selection of a particular one of said switching members, other lines, and means controlled. by said switching members for connecting the corresponding line to any of said other lines.

19. The combination in a switching device of aplurality of operating members, switching members, a plurality of lines, one for each switching member, means for causing a pair of said operating members to act cojointly in the selection of a particular one of said switching members, other lines, and means controlled by said one of said switching members for connecting the corresponding line to any of said other lines.

In witness whereof, I hereunto subscribe my name this 21st day of April A. D., 1922.

CHARLES J. HENDRICKSON. 

